From the perspective of power generation, the greater the power of the photovoltaic modules initially installed, the higher the power generation from the perspective of installation, the power generation with the installation angle is about 30% higher than that without the installation angle; in the case of home offices, the family can use 70% of the system's power generation. In addition, in non-home situations, it is usually less than 50%; The 850 Wp system is freely installed in Berlin and has an annual power generation of about 800 kWh/year, which is equivalent to a total saving of about 230 euros, less than 400 kWh and the total cost is less than 150 euros.